BS ISO 11783-4 pdf download

BS ISO 11783-4 pdf download Tractors and machinery for agriculture and forestry — Serial control and communications data network Part 4: Network layer
1 Scope
ISO 11783 as a whole specifies a serial data network for control and communications on forestry oragricultural tractors and mounted， semi-mounted,towed or self-propelled implements.lts purpose is tostandardize the method and format of transfer of data between sensor，actuators,control elements andinformation storage and display units, whether mounted on, or part of, the tractor or implement. This part ofISO 11783 describes the network layer，which defines the requirements and services needed forcommunication between control functions(CFs) in different segments of the ISO 11783 network.The varioustypes of network interconnection units are defined in this part of ISO 11783.
2Normative references
The following referenced documents are indispensable for the application of this document. For datedreferences,only the edition cited applies. For undated references,the latest edition of the referenceddocument (including any amendments) applies.
ISO 11783-1,Tractors and machinery for agriculture and forestry — Serial control and communications datanetwork — Part 1: General standard for mobile data communication
ISO 11783-2，Tractors and machinery for agriculture and forestry —Serial control and communications datanetwork — Part 2: Physical layer
ISO 11783-3,Tractors and machinery for agriculture and forestry — Serial control and communications datanetwork – Part 3: Data link layer
ISO 11783-5,Tractors and machinery for agriculture and forestry—Serial control and communications datanetwork —-—Part 5: Network management
ISO 11783-7,Tractors and machinery for agriculture and forestry —Serial control and communications datanetwork – Part 7: lmplement messages application layer
ISo 11783-9,Tractors and machinery for agriculture and forestry —Serial control and communications datanetwork – Part 9: Tractor Ecu
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11783-1 and the following apply.
3.1
address space
allowable range of addresses on a particular subnetwork
NOTE When an NIU separates network segments, the same address can be used by CFs on each side of the NIU.
3.2
connection
establishment of dynamic virtual addresses in an NIU (network interconnection unit) for sending and receiving messages between CFs on different network segments that have different address spaces
3.3
network interconnection unit
NIU
electronic control unit (ECU) used for interconnecting networks or network segments
3.4
port
network segment interface to an NIU
NOTE An NIU has two or more ports connected to different network segments.
3.5
port pair
two ports of an NIU indicating the direction of data flow from one segment to another segment
3.6
transparent
CF which provides services to another CF without it being aware of the source of these services NOTE The CFs need not be aware there is an NIU connecting the CFs together.
3.7
virtual CF
apparent CF established by an NIU on one network segment using the same NAME of the actual CF on a different network segment
3.8
actual CF
CF established directly by an ECU on the network segment
4 Description
4.1 Role of the network interconnection unit (NIU)
4.1.1 Message transfer
4.1.1.1 General
When multiple segments exist in a network, the NIU provides the means of transferring messages from one segment to another. The unit transfers individual message frames between two or more ports, of which there is one per segment.